Refer to the exhibit.  Which Virtual Router Redundancy Protocol （VRRP） statement is true about the roles of the master virtual router and the backup virtual router？（）

• A、Router A is the master virtual router， and Router B is the backup virtual router. When Router A fails， Router B will become the master virtual router. When Router A recovers， Router B will maintain the role of master virtual router.
• B、Router A is the master virtual router， and Router B is the backup virtual router. When Router A fails， Router B will become the master virtual router. When Router A recovers， it will regain the master virtual router role.
• C、Router B is the master virtual router， and Router A is the backup virtual router. When Router B fails， Router A will become the master virtual router. When Router B recovers， Router A will maintain the role of master virtual router.
• D、Router B is the master virtual router， and Router A is the backup virtual router. When Router B fails， Router A will become the master virtual router. When Router B recovers， it will regain the master virtual router role.